Use the explicit rule given to write recursive rule for the geometric sequence:

a_n = 20(3)^(n-1)

  see below

Step-by-step explanation:

You know the relationship between the explicit rule and the recursive rule for a geometric sequence is ...

The given explicit rule tells you a1 = 20, r = 3, so you know the recursive rule is the one shown below.

Option B

Step-by-step explanation:

A) a1 = 3

a2 = 3×20

an = 3 × 20^(n-1)

B) a1 = 20

a2 = 20×3

an = 20 × 3^(n-1)

C and D are not geometric

b

step-by-step explanation: